It has long been an object of the prior art to obtain a match for impedance of an RF source to that of a line or antenna. See U.S. Pat. No. 2,855,599 as a teaching of a way to arrive at this object and for the reasons such is desirable.
However, while this has been a long standing object, no one is known prior to this invention to have found a practical, inexpensive and compact means of packaging such elements to permit universal economical utilization. It is therefore the principal object of this invention to obtain a compact concentric operative relationship of loading coil and coupling coil for impedance matching of an RF source to a line or antenna.